Ocular delivery systems for the administration of antibody therapeutics

Antibodies (Abs) have been extensively used as a powerful tool for targeting proteins based on their immunologic functions such as antigen recognition and pathogen neutralization. In particular, monoclonal Abs (mAbs) and fragments can be promising drugs in clinics owing to their sensitivity and specificity. The controlled release of Ab drugs after local delivery would lead to their prolonged exposure at the disease site, thereby improving the disease condition. In this review, we illustrate the activity of clinically used anti-vascular endothelial growth factor drugs, including aflibercept (Eylea; Regeneron Pharmaceuticals, Bayer Pharma), bevacizumab (Avastin; Genentech, Novartis), and ranibizumab (Lucentis; Genentech, Novartis), in ocular diseases such as wet age-related macular degeneration and myopic choroidal neovascularization. For controlled and prolonged release of the aforementioned drugs after ocular administration, recent approaches using liposomes, hydrogels, and nanoparticles have been introduced. In addition, the evaluation methods to meet the requirements of clinically used Abs are discussed. On the basis of the findings of our review, we can suggest that an ocular delivery system can be a promising platform to overcome the limitations associated with clinically used Abs.